Orogenic greenstone gold deposits hosted in a number of different styles of lodes. The Granny Smith lodes comprise vein stock works localised by a northerly trending shear at the margin of a granodiorite. The Wallaby lodes are flat lying alteration zones hosted within magnetite amphibole altered conglomerate.

The Granny Smith region is dominated by the Mt Margaret Dome in the northwest and the Kirgella Dome in the southeast. These domes are flanked to the east and west by north-northwest striking shear zones, with the central zone between the two domes being dominated by north to northnortheast-striking sigmoidal shear zones. These distinctly different strikes to the shear zones developed early in the tectonic evolution and resulted in a favourable architecture for late-stage orogenic gold mineralisation at Wallaby and Granny Smith.

Orogenic greenstone gold deposits are hosted in different styles of lodes. The lodes comprise vein stock works localised by a northerly trending shear at the margin of a granodiorite. The Wallaby lodes are flat lying alteration zones hosted in magnetite amphibole altered conglomerate. Mineralised zones show moderate to long-range geological continuity and short-range grade continuity.

Wallaby underground mine is accessed via a single truck haulage decline from a portal in the Wallaby open pit. Ramp gradient is 1:7, decline and truck access profile are 5.2m wide x 5.7m high and ore drive profile is 4.6m wide x 4.6m high.

Mining methods employed include room and pillar, bulk stopes and long-hole open stoping. The Zone 135 bulk stopes reflect the deepest mining in the LoM plan at Wallaby at ~1,450m below surface. Ground support, pillars and paste fill are designed to manage seismic activity. Operations utilise owner mining. Road haulage carts ore to the processing plant from the decline portal. Current mining focuses on extracting Zone 110/120.

Granny Smith operates a single TSF that comprises three compartments, known as cells 1, 2 and 3. A fourth cell will be constructed in 2021 next to cell 3 to provide additional tailings capacity for the rest of the LoM. The mine also has one ore stockpile in the LoM plan.

The Granny Smith Gold mine Processing Plant was originally designed and commissioned to treat oxide gold ores mined from the Goanna, Granny and Windich pits. The plant has been periodically upgraded, based upon production requirements and ore types. The processing plant currently implements a campaign milling schedule, processing the sulphide ore mined from the Wallaby underground deposit.

The plant consists of a two-stage fresh ore crushing circuit with closed circuit screening, a standard SAG and Ball mill (SABC) grinding circuit, a gravity recovery circuit, a mechanically agitated Leach/Carbon in Pulp (CIP) circuit, a pressure Zadra elution circuit, a tailings gravity recovery circuit with regrind, a doré gold production facility, a carbon reactivation circuit, and
a thickened tailings storage facility (TSF).